Printer&#39;s blanket.



W. M. CARMICHAEL.

PRINTER'S BLANKET.

APPLICATION FILED FEB. 2B. |916.

1 ,246,23 1 Patented Nov. 13, 1917.

mueM/toz .3M MQW.

WILLIAM u. enfermement, or arteria, croacia.

EBINTEES BLANMT.

Specification of Letters Patent.

Application tiled February 28, i916. Serial-Eo. 81,0%.

D of which the following is a speciication.

My invention relates to printers blankets, and vone object is to improve upon such blankets, enable time to be saved, eliminate the make-ready process and lengthen the life of type and cuts.

Another object of this invention is to provide a blanket which will produce a hetter average of work with more uniformity and hrilliancy of color, and finally reduce K the strain of impression, thereby increasing 5oproduce a hlanliet ,or t

the life of the printing machinery anda'voiding the necessity of frequently repairing damaged or worn parts.

To produce a proper impression from vtype or plates, it is essential, in order to obtain the best results, to vary the pressure on certain portions of the form so as to insure the taking u of the proper amount of ink to produce suc variations or uniformity in shade as are appropriate. This heretofore has 'heen accomplished by pasting thicknesses of paper or other suitable material over the weaker portions of the oints, so as to raise the surface at these points after which the necessary graduations of shade or tone are obtained byscraping the surface. This process, commonly termed makeready, is objectionable, however, as the irregular surface of the make-ready is so near the printing surface of the form that a number of sheets of paper must he interposed 1between the latter and said makeready to secure a proper` surface for the impression, lout such interposed material tends to produce what might loe termed a dahby impression surface, which detracts materiali .from the sharpness and clearness of the print, and especially is this true with respect to illustrated worh, since the latter requires a hard, smooth yet deriihle impreson surface. A

Edorts have in the past, heen made to pan having a hard and month surface, ut these have, to a great extent, provedunsuccessful, owing to the fact that in providing such anl impression surface, the other essentials, namely flexibility and resiliency werevsacriced, coneequently these blankets` do not lreadily adapt themselves to the inequalities usual 1n printing forms, the inaccuracies in the construction of printing machinery, as well as the Asagging of some of the parts thereof, and, hence, produce inferior work. lin this connection, experience indicates, to obtain the best result with a blanket having a hard and smooth impression surface, the latter should he comparatively thin but not brittle, and have a yielding supporting means which will not have undue reflex action on 'any part of said impressionv surface, hy

reason of undue distortion atsome other part of the yielding support. To meet these requirements, a yielding supporting means,

Patented Noy i3, Digi?,

preferably formed of ground cork, having a suitable binder and faced on opposite sides with fabric, is provided with a superposed sheet of erilole material treated with preparations hereinafter to he stated, so as to resent a hard and smooth impression surace. This construction provides a support capable of adaptation to the inequalities of theform surface, yet one having an impression surface of sucient exibility to readily respondl to the action of its underlying support. Uf course, it is to he understood that, while the yielding support formed as outlined is preferable, itmay he constructed in any manner and of any material possessing the desired requisites, as, for instance, ruhher, and other similarly functioning materiah l ln the' accompanying drawing, inl which co ending parts are indicated hy sirm- Figure l is a perspective fragmentary view of my improved hlanhet.

ln the illustrated embodiment characterizing my invention, there is shown a yielding support l, having a bodyportion 2 formed of a suitable ciunposition preferably embodying ound cork held together hy any suitable hinder. Both sides of the loody' 'portion are'faced with faloric 3, which serves liti@ as a reinforcement to prevent said ccmposition from cracmng when in use. To the yielding supporte-il with the desired imgpreeeion surface, itscuter surface has pomldd tioned thereon a thin sheet of fabric t, preferehly domestic muslim. The outer surface of this muelinsheet 4l is then treatw'with two coats of shellac 5, each coating having a drying intervm of appintimately' twelve' ire hours. When the last coat of shellac has dried suciently, a thin coat of asphalt-um d.

i is then applied thereto, andpermitted to/ dry. Treating the muslin in this manner renders it somewhat analogousto the pressboards now used in this art, but with yield ing qualities, however, superior to the latter. `While the asphaltum application gives to the muslin surface the requisite hardness to thereby render it capable ofproducing illustrated work of great clearness and brilL li'ancy. An impression surface, formed as outlined, and acting in conjunction with the yieldable support hereinbefore mentioned, has all -of the advantages of su'ch yielding support, in so far as resiliency lis concerned, with the addition of the greatly to be desired hard and flexible impression surface, as will be readily understood without further discussion. A blanket, constructed in accordance with the rinciples of this invention, materially re uces the cost of illustrated work, as it enables clear, sharp illustrations to be made on even inferior grades of paper.

Experience has conclusively demonstrated the fact that a muslin sheet, treated as aforesaid, and coperating with a yieldable support, will not crack, even under the most extreme pressure, but will readily yield in accordance with the movement of its underlying support, as' will be clearly understood without further discussion.

The fabric, Iconstituting the impression surface, is aiixed to the yielding support in any. suitable manner, and the blanket, thus arranged, is mounted on the impression cyly inder by the usual clamps, as will be readily understood without further discussion.

In the light-of the foregoing, it will be observed that I have provided a blanket or tympanwhich is comparatively inexpensive, simple in -construction and one which will materially increase the quality of the work in the art under discussion.

Although in the foregoing, I have set forth certain elements as best adapted to perform the functions allotted to them, nevertheless, it is to be understood that various minor changes as to form, substance etc., may be resorted to within the scope of the appended claims without departing from or sacrificing any of the princlples of this invention.

Having now described my I claim is 1. As a new article of manufacture, a printers blanket comprising a resilient sup,- porting member anda superposed impres sion surface, embodying a fabric layer permeated with a stiifening agent and having a coating of asphaltum on its exterior surface, substantially as and for the purpose set forth.

2. As a new article of manufacture, a printers blanket comprising a resilient supporting member, and a superposed impression surface, embodying a fabric layer having on its exterior surface a coating of shellac, with an overlying coating of asphaltum,

invention, what 'substantially as and for the purpose set forth.

3, As a new article 'of manufacture, a blanket consisting of a yieldable base provided with an impression surface permeated 'With a stidening agent and having a hardening coating of a bituminous nature.

4. As a new article of manufacture, a blanket consisting of a yieldable supporting member and a superposed impression surface embodying a fabric layer having a hardening coating of a bituminous nature on its exterior surface.

W. M. CARMICHAEL.

Witnesses: A e

WILL T. GORDON, WHARTON Ol. Wilson. 

